The national average for a gallon of diesel fell 13.6 cents to $5.432, the fourth straight week costs have dropped, according to the U.S. Energy Information Administration. "Demand has plummeted in anticipation of a recession, in addition to fewer consumers traveling than normal for the July holidays," reads an article from FleetOwner. "National crude oil stocks also are up, which usually brings prices down."

Even with the slight price drop, diesel costs still sit roughly $2 higher than one year ago, putting pressure on truckers and farmers. "People pay less attention to diesel prices because people aren't going to the pump and using it," Matt Smith, lead oil analyst at Kpler, a research firm, told the Associated Press. "But diesel has a more far-reaching impact and is already having a real big impact across the economy."

According to Oil & Gas Journal, global oil production rose by 690,000 barrels last month, and U.S. petroleum inventories are up. But an increase in oil production has not single-handedly lowered diesel costs.

"Global economic headwinds are pushing oil prices lower and less expensive oil leads to lower pump prices," said Andrew Gross, spokesman for motor club AAA, told FleetOwner. "And here at home, [passenger vehicles] are fueling up less, despite this being the height of the traditional summer driving season. These two key factors are behind the recent drop in pump prices."